We recently installed Active Directory Federated Services version 2.0 on Windows Server 2008. In the course of testing, we had to delete and re-install. We followed instructions found here, here, and here. Sadly, IIS kicked up an error “application pool cannot be deleted because it contains 1 applications” when we tried to delete ADFSAppPool. After many attempts, this is how we deleted ADFSAppPool. This method can be used to delete any application pool in IIS 7.5.

Removing ADFSAppPool, step 1

1) Open IIS Manager. Go to “Application Pools”. Select ADFSAppPool. Press “View Applications” on the right side bar.

Removing ADFSAppPool, step 2

2) You should see a single item in the list of “Applications” using the application pool ADFSAppPool.

Removing ADFSAppPool, step 3

3) Double-click this entry. You should see a dialog box titled “Select Application Pool” with ADFSAppPool selected.

Removing ADFSAppPool, step 4

4) Open the drop-down menu. Select DefaultAppPool.

Removing ADFSAppPool, step 5

5) Click “OK” to close the dialog box.

Removing ADFSAppPool, step 6

6) The Application should now list DefaultAppPool as its application pool.

Removing ADFSAppPool, step 7

7) Click on “Application Pools” in the left sidebar. ADFSAppPool should have 0 applications using it. Press “Remove” in the right sidebar or from the right-click menu.

Removing ADFSAppPool, step 8

8) Click “Yes” to confirm that you want to remove.

Removing ADFSAppPool, step 9

9) Voila! The offending Application Pool has been removed.

Hope this tip helps. If it does, please add a comment saying just that.